JP3844763B2 - Epoxy resin composition for room temperature / low temperature curable prepreg, prepreg and method for curing the same - Google Patents

Description

  The present invention relates to a normal / low temperature curing type prepreg epoxy resin composition having excellent storage stability, a prepreg, and a curing method at the time of molding the prepreg, and particularly troublesome work conventionally performed by hand lay-up. The present invention relates to a room temperature / low temperature curable prepreg excellent in storage stability that can be used for a wide range of fields such as sports / leisure and civil engineering as well as a conventional method, and a curing method thereof.

  Conventionally, the epoxy resin used for the prepreg has a considerably high curing temperature of 120 ° C. or higher, and it has been impossible to integrally form a prepreg by using a foam material such as urethane or acrylic as a core material. Recently, however, many low-temperature curable prepregs have been proposed in consideration of energy saving and productivity in forming a general prepreg. It is a method using a latent curing agent that does not cure at room temperature or is in a B-stage state (semi-cured state) but is cured at a temperature of 80 ° C. or higher. For example, Patent Document 1, Patent Document 2, and Patent Document 3 include those using an active hydrogen and an amine adduct type curing agent having a catalytic functional site in the molecule. Alternatively, Patent Document 4, Patent Document 5, and Patent Document 6 include those using a microcapsule type curing agent. However, in order to cure all of them, heat curing at 80 ° C. or higher is necessary.

  On the other hand, conventional FRP tanks and towers are manufactured, or lining methods such as industrial and sewerage are applied by hand-laying up a room temperature curing type epoxy resin or unsaturated polyester resin to short fibers or long fibers. It has been adopted. Recently, in the civil engineering field, Patent Document 7 proposes a method for repairing or reinforcing a civil engineering structure by applying a room temperature curing type epoxy resin to a long fiber sheet by a hand lay-up method. Yes. However, both of these are mixed on site with the main agent and curing agent to adjust the epoxy resin, and since the pot life is short, it must be applied in a limited time so that no air remains on the fiber. In addition, it has the disadvantage of being unfavorable for safety and health.

  On the other hand, Patent Document 8 uses a long fiber prepreg in which fibers are impregnated with an epoxy resin that is cured at 70 ° C. or higher, and Patent Document 9 impregnates an epoxy resin that does not substantially contain a curing agent. The one using long fiber prepreg has been proposed, but this is also cured at room temperature by using room temperature curing type epoxy resin solution or room temperature curing type curing agent solution dissolved in thinner or MEK on the surface of the prepreg. However, there is also a drawback that the trouble of the hand lay-up method and the problem of safety and health cannot be solved because of the use of a solvent, and the curing is liable to occur.

On the other hand, Patent Document 10 proposes a method using a long-fiber prepreg that does not require hand layup, but is heated to a high temperature of 50 ° C. or higher by an infrared lamp or an electric heater after being applied on site. Need to be cured. According to this method, since no solvent is used, there is no problem in terms of safety and hygiene, but an operation of heating and curing is still necessary, and it is not yet satisfactory in terms of bothering.
Japanese Patent Laid-Open No. 3-115331 JP-A-5-310892 JP-A-5-262903 JP-A-4-31420 JP-A-4-325518 JP-A-5-262903 JP-A-3-224901 JP-A-3-224966 JP-A-5-39673 JP-A-1-197532

  In view of the current situation, the present invention takes into consideration energy savings, productivity improvement, etc., especially in the repair and reinforcement of structures using fiber sheets or prepregs, compared to conventional low-temperature curing type prepregs, with a large heating device. Thus, it can be cured at a lower temperature or at a normal temperature, and can solve the problems of safety and hygiene and troublesomeness as compared with the conventional hand lay-up method. An object of the present invention is to provide a composition, a prepreg, and a curing method thereof.

That is, the present invention includes the following A, B, D and E
A: Epoxy compound B having at least two or more glycidyl groups in one molecule; Polymercaptan compound
D: A microcapsule-type latent curing accelerator that has a potential at room temperature and can be a curing accelerator for a polymercaptan compound.
E: Boric acid ester compound
Characterized in that it contains a low-temperature curable prepreg epoxy resin composition, and a fiber-reinforced prepreg, characterized in that impregnates reinforcing fibers the epoxy resin composition.

The epoxy resin composition for a prepreg of the present invention is a compound that has a potential of 10 to 100 parts by weight of the B component with respect to 100 parts by weight of the above A component and can be a curing accelerator for the polymercaptan compound at room temperature. 1 to 20 parts by weight of a certain D component and 0.1 to 7.0 parts by weight of an E component which is a boric acid ester .
Preferably the D component of the case is a microcapsule-type latent curing accelerator, further, in order to ensure the storage stability, are those having free a component E boric acid ester compound. The present invention also relates to a low-temperature fast-curing prepreg characterized by impregnating reinforcing fibers with such an epoxy resin composition for prepreg.

  The present invention is a room temperature curable prepreg epoxy resin composition that has excellent storage stability and can be cured at room temperature. Compared to a conventional low temperature curable prepreg resin at about 80 ° C., the present invention is energy saving and productive. Very good in terms. In addition, the present invention is greatly improved in troublesomeness compared to a method in which two liquids are mixed and applied by a hand lay-up method, and no solvent is used. This is a room temperature curing method that has few sanitary problems and that can solve problems such as curing characteristics and surface condition of the cured product, and is very useful in industry.

  The present invention will be described in detail below. First, the A component and B component common to all claims of the present invention will be described. The epoxy compound used as the component A is not particularly limited as long as it has at least two glycidyl groups in one molecule, and any compound can be used. For example, bisphenol A type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, bisphenol F type epoxy resin, other alicyclic epoxy resins, bisphenol S type epoxy resin, etc. Or 2 or more types can be mixed and used.

  Commercially available bisphenol A type epoxy resins include espoxy SA-115, espoxy SA-134, espoxy SA-011, espoxy SA-019, espoxy SA-7020 (manufactured by Nippon Steel Chemical Co., Ltd.), Epicoat 828 Epicoat 834, Epicoat 1001, Epicoat 1001, Epicoat 1002, Epicoat 1004 (above, manufactured by Yuka Shell Epoxy Co., Ltd.), Araldite GY-250, Araldite GY-260, Araldite 6071 (above, Nippon Ciba Geigy ( Etc.) can be used.

  Commercially available cresol novolac type epoxy resins include Espoxi SCN-701P, Espoxi SCN-702P, Espoxi SCN-703P, Espoxy SCN-704P (manufactured by Nippon Steel Chemical Co., Ltd.), Araldite ECN-1273, Araldite ECN -1280 (Nippon Ciba Geigy Co., Ltd.) or Sumitomo Chemical Co., Ltd. ESCN-220 series can be used.

  Commercially available phenol novolac type epoxy resins such as Espoxi SPN-638 (manufactured by Nippon Steel Chemical Co., Ltd.), Epicoat 152, Epicoat 154 (above, manufactured by Yuka Shell Epoxy Co., Ltd.) and the like are commercially available. Is available. As the bisphenol F type epoxy resin, Epicron 830 (manufactured by Dainippon Ink & Chemicals, Inc.) can be used.

  Next, the B component polymercaptan compound common to all of the present invention is a compound having a mercaptan terminal group, and includes liquid polymercaptan and polysulfide. The polymercaptan compound used here does not cure at room temperature or has a very slow curing reaction unless an amine compound in the catalyst C component described later or the D component of the curing accelerator is present. The polymercaptan compounds used in the present invention, which are specifically marketed, include EpiCure QX-40 (manufactured by Yuka Shell Epoxy Co., Ltd.) and Adeka Hardener EH-317 (manufactured by Asahi Denka Co., Ltd.). ), Thiocol LP-70 (manufactured by Thiocol Co., Ltd.) and the like, but are not limited thereto.

Furthermore, as the amine compounds in component C which is common to a room temperature curable prepreg epoxy resin composition of the present invention, first, it may be any secondary or tertiary amines, poly mercaptan compound of component B It must have a function as a catalyst for room temperature curing and be capable of microencapsulation. From such a viewpoint, tertiary amine is particularly preferable. Specific examples include 2,4,6-tris (dimethylaminomethyl) phenol, 2- (dimethylaminomethyl) phenol, benzylmethylamine, and the like, but are not limited thereto.

In this onset bright, when coexisting with intact A and B components an amine compound described above, it is impossible to produce a prepreg cured rapidly react even at room temperature progresses. Or even if it can be manufactured, the storage stability is very poor. To solve this problem, it is possible to suppress the curing reaction by the A or B component in microcapsules, in this onset bright, it utilizes an amine compound as a microencapsulated component C is there. This is because the A component and the B component are main components in which the curing reaction proceeds at approximately the same amount, and since the content is very large, the microcapsule is destroyed during prepreg production, and the storage stability deteriorates. On the other hand, when curing is performed, the amount of microcapsules to be destroyed increases, resulting in deterioration of workability or non-uniform curing. In contrast, the amine compound acts as a catalyst, and its content may be much smaller than that of the A and B components, and further, storage stability, curing workability or curing characteristics are improved.

  Here, the type of microcapsule has good storage stability, and a compression fracture type is convenient for curing at room temperature. As a shell material, it can withstand compression in the 90 ° direction, but it breaks by shear compression. Easy thing is good. The shell material is not necessarily limited to a material as long as the above conditions are satisfied. Specifically, acrylic acid, methacrylic acid, acrylic acid ester (methyl ester, ethyl ester, etc.), methacrylic acid ester (methyl ester, ethyl ester, etc.), vinyl acetate, vinyl chloride, vinylidene chloride, ethylene, styrene, There are polymers such as divinylbenzene and ethylene glycol dimethacrylate.

Method of making a compression fracture type of microcapsules definitive to the onset Ming, but are not limited to, for example, a core component and a polymerization initiator to be contained as a monomer having such a polymerizable unsaturated bond of the acrylic acid and styrene Is generally mixed and dispersed in a medium containing an appropriate emulsifying dispersant so that oil droplets having a target particle size are formed, and the monomers are polymerized. The target particle size, amount of inclusion, and pressure strength are adjusted by selecting the type of monomer component, the ratio of the monomer component to the inclusion component, the amount of the emulsifying dispersant and the type dispersion conditions.

  If it demonstrates in detail about C component, the average particle diameter of a microcapsule has preferable 1-20 micrometers. When the thickness is less than 1 μm, the shell material unnecessary for curing tends to increase in comparison with the core material necessary as a catalyst for the curing reaction, that is, the amine compound in the C component. In other words, the shell material does not react with the epoxy resin and acts as an impurity that adversely affects the strength of the cured composite material, so that the amount is preferably as small as possible. On the other hand, when the thickness exceeds 20 μm, the resin impregnation into the fibers is uneven and easily causes poor curing.

  Next, it is the compounding quantity of A, B, and C component. As mentioned above, since the reaction proceeds with an equivalent amount, it is preferable that the A component and the B component are added in substantially equivalent amounts. Moreover, since C component is a catalyst, a small amount may be sufficient. Depending on the type of epoxy compound, polymercaptan compound and amine compound to be used, the addition amount may be changed as appropriate. However, with respect to 100 parts by weight of the total amount of component A, 10 to 200 parts by weight of component B and 0.1 parts of component C are added. It is preferable to blend ~ 20 parts by weight. When the component B is less than 10 parts by weight, the amount of the polymercaptan compound as a curing agent is insufficient, which tends to cause curing failure, which is not preferable. When the amount exceeds 200 parts by weight, the amount of the curing agent is too large, and the characteristics of the composite material are deteriorated. When the component C is less than 0.1 parts by weight, the catalytic effect is lowered, resulting in poor curing, which is not preferable. On the other hand, if it exceeds 20 parts by weight, not only will there be an increased risk of breaking the microcapsule during prepreg production, but it will also increase the components unnecessary for curing, which will reduce the physical properties of the composite material, After all it is not preferable.

Method for producing a fiber reinforced prepreg using the present onset Ming cold-setting prepreg epoxy resin composition can be a common method, specifically, there is a hot-melt method or a solvent method is not particularly limited . However, in particular, care must be taken not to break the C-component microcapsules during manufacture. If the microcapsules are broken, the curing reaction proceeds rapidly and the storage stability deteriorates. In order to avoid these, when using the temperature and pressure at the time of resin impregnation or a solvent, it is possible to appropriately consider the type. Here, when there is a possibility of destroying the C component microcapsules during the production of the prepreg, a method of attaching the C component to the surface of the prepreg after producing the fiber reinforced prepreg containing the A component and the B component. You can also take Examples of the fiber used in the present invention include glass fiber, carbon fiber, aramid fiber, polyethylene fiber, and woven fabric and nonwoven fabric thereof, but are not particularly limited.

  Next, a room temperature curing method for the fiber reinforced prepreg will be described. In the formation of a general prepreg, first, it is necessary to attach and press the prepreg on the surface to be bonded so as not to collect air. When the above-described C component of the present invention is used in a microcapsule, the C component microcapsule must be destroyed and the core material released in the prepreg molding stage in order to cure at room temperature. Methods for destroying the microcapsule include pressurization, heating, or irradiation with electromagnetic waves. In the case of heating or electromagnetic wave irradiation, it is not preferable from the viewpoint of workability, energy saving or danger. However, according to the present invention, there is an advantage that the microcapsules can be destroyed simultaneously with the application and pressurization to the surface to be bonded. The method for pressurization is not particularly limited as long as the microcapsules can be broken, but it is convenient to use a roller or vibrators capable of shear compression. Moreover, when using the prepreg with the C component attached to the surface of the fiber reinforced prepreg using the A component and the B component, a dryer, a heating roller, etc. It is desirable to pressurize together with a heater.

Next will be described the low temperature rapid curing type prepreg epoxy resin composition and a prepreg of the present invention.
A, B component of the above-ash is used. The D component has a latent property at room temperature and can be a curing accelerator for the polymercaptan compound as the B component is a Lewis base, and hardly accelerates the curing reaction of the polymercaptan compound at a temperature below room temperature, but is 45 ° C. Above, it is a compound that accelerates curing fairly rapidly. Generally, as a curing accelerator for polymercaptan, a tertiary amine such as trisdimethylaminomethylphenol or a salt thereof, or a primary or secondary amine having active hydrogen such as triethylenetetramine or metaxylenediamine is used. Yes. By using these in combination with polymercaptan, low temperature rapid curing is possible even at room temperature or lower. However, the disadvantage is that the pot life is within a few hours at room temperature and the handleability is inconvenient. Of course, prepreg using this is impossible from the viewpoint of storage stability.

  Therefore, in the present invention, in order to enable prepreg formation using a polymercaptan compound as a low-temperature fast-curing curing agent, latent curing acceleration is not exhibited at room temperature or is very slow even if it is exhibited. Is used. As a curing agent having a latent property at room temperature, it can be cured at a low temperature of about 80 to 100 ° C. alone, but since it is an amine compound, it also has a function as a curing accelerator. Because it is. Therefore, by using these for dicyandiamide and acid anhydrides that require high temperature curing conditions of around 150 ° C., which have been conventionally used, curing at a lower temperature is realized in a shorter time.

  By the way, the polymercaptan series has a fast curability even at a low temperature of room temperature or lower by using an amine compound as a curing accelerator, so that it is not necessary to use such a latent curing agent. There is no example. The latent curing agent corresponding to the present invention includes a microcapsule type having an amine compound as a core layer, or an amine adduct type in which an epoxy compound, a urea compound or an isocyanate compound is adducted with an amine compound. Specifically, as for the microcapsule type curing agent, Asahi Kasei Co., Ltd .: Trade name Novacure and Amine Adduct type curing agent, Ajinomoto Co., Inc .: Trade name Amicure, Fuji Chemical Co., Ltd. ): Product name Fuji Cure, manufactured by ACR Co., Ltd .: Product name ACR Hardener, Shikoku Kasei Co., Ltd. product name cure duct, etc., but is not limited to this, one or more selected as appropriate Can be mixed and used.

  Among these, the microcapsule type is covered with a shell layer and does not come into direct contact with the amine compound in the core layer and has an excellent storage stability. By using these in combination with a polymer taptan compound, it has excellent storage stability, and at a lower temperature and in a shorter time than a conventional low temperature curing type prepreg that requires curing conditions at 80 ° C. for 30 minutes, for example, 80 ° C. Then, it has been found that curing can be carried out within 10 minutes even at 60 ° C. for about 20 minutes.

  Next, the blending amounts of components A, B, and D, the polymercaptan-based curing agent reacts with the epoxy compound at an approximately equivalent amount, and may be added in an equivalent amount, but from the combined use of a curing accelerator. The curing accelerator itself has a function as a curing agent, and therefore may be considerably less than the equivalent amount. Each addition amount may be changed as appropriate depending on the curing conditions, that is, the curing temperature and the curing time. However, from the viewpoint of curing characteristics and storage stability of the prepreg, component A, that is, at least two or more glycidyl per molecule. 1 to 100 parts by weight of the epoxy compound having a group and 10 to 100 parts by weight of the B component, that is, the polymercaptan compound, and D component, that is, a compound that has a potential at room temperature and can be a curing accelerator for the polymercaptan compound. It is preferable to contain -20 weight part.

  This is because when the polymercaptan compound is less than 10 parts by weight, the low-temperature rapid curing performance is inferior or poor curing occurs. On the other hand, when the amount exceeds 100 parts by weight, curing failure is caused. Next, if it is less than 1 weight part about a hardening accelerator, the effect of a hardening acceleration | stimulation is not enough and low temperature rapid hardening performance will be inferior. On the other hand, when the amount exceeds 20 parts by weight, a slightly better effect is recognized with respect to the low-temperature rapid curing performance, but conversely, there is a disadvantage that the storage stability is lowered.

Next, regarding the storage stability, in addition to the A, B and D components, the E component, that is, the borate ester compound B (OR ₁ ) (OR ₂ ) (OR ₃ ) (1) represented by the following general chemical formula (1)
_(However, R 1 to R ₃ represents a hydrogen atom, an alkyl group or an aryl group)
0.1 to 7 . By containing 0 part by weight, it can be further improved. In the present invention, even when the E component is not contained, the storage stability is quite good. However, for example, when it is left at around 30 ° C., it is still insufficient. This is because when the storage temperature is as high as about 30 ° C., even the latent curing agent used in the present invention dissolves or elutes in a very small amount and gradually accelerates the curing reaction of the polymercaptan compound. . Thus, the present inventors have found that the storage stability can be further improved by quantitatively blocking only the latent curing agent dissolved or eluted during storage with a borate ester compound.

Here, the borate compound is formed by chemically bonding and blocking the Lewis base of the latent curing agent that dissolves or elutes during storage before acting as a curing accelerator for the polymercaptan compound. It is thought that the function is lost. Therefore, the boric acid ester compound to be contained is 0.1 to 7 in terms of storage stability and a curing rate during heat curing. It is preferable to contain 0 part by weight. If it is less than 0.1 part by weight is because the storage stability effect is not so much exerted, also 7. When the amount exceeds 0 part by weight, the storage stability is very excellent, but conversely, the curing acceleration effect of the latent curing agent is inhibited at the time of heat curing, so that the curing rate becomes slow. Such a boric acid ester compound may be a simple substance or a mixture of an epoxy resin or the like, and examples of commercially available products include Cure Adduct L-01B (manufactured by Shikoku Kasei Co., Ltd.). It is not limited to this.

  In the present invention, in addition to components A, B, D, and E, additives such as flame retardants, antioxidants, flow control agents, or tack preparation agents, as long as they do not affect the low-temperature fast curing performance as necessary. A small amount of can be added. The manufacturing method of the fiber reinforced prepreg using the above-mentioned low-temperature fast-curing type epoxy resin composition for prepreg may be a general method, specifically, a hot melt method or a solvent method, but is not particularly limited. However, in particular, care must be taken not to start the curing reaction by raising the temperature more than necessary during production. This is because the storage stability decreases as the curing reaction proceeds.

  In the epoxy resin composition of the present invention, the prepreg production at 40 ° C. or lower is preferable because the curing reaction gradually proceeds when the temperature exceeds 40 ° C. These are possible by appropriately considering the type of epoxy resin, the temperature and pressure at the time of resin impregnation, or the type of solvent used. Moreover, it is preferable to preserve | save at 0 degrees C or less like normal prepreg at storage below normal temperature. Examples of the fiber used in the present invention include glass fiber, carbon fiber, aramid fiber, polyethylene fiber, and woven fabric and nonwoven fabric thereof, but are not particularly limited.

The method for curing flop prepreg is what may be a method but if it is possible to heat to temperatures in excess of 40 ° C., not dare to be heated at high during periods of temperature. In order to shorten the low temperature period and the curing time that require heating, it is easy to use equipment such as a dryer, jet heater, plastic jet sheeter, infrared heater, heating roller or iron.

Next, the present invention will be described in more detail with reference to examples.
The evaluation methods in the following examples are as follows.
・ Storage stability: Tactile evaluation of tackiness of prepreg after standing at 15 ° C. for 10 days ○ ・ ・ ・ Good (no change)
Δ: Slightly good (slightly cured but no problem for use)
× ... defect (cannot be used after curing)
・ Attachment workability: Workability / safety and hygiene when a prepreg or sheet is attached to a cement surface that has been treated with an epoxy primer; Then, after standing for 1 week after heating, it was immersed in acetone for good evaluation of the cured state .... No change, fully cured failure .... Surface was swollen or (partly) dissolved, resulting in poor cure.・ Surface condition after curing; surface condition when visually observed after curing ○ ・ ・ ・ Good △ ・ ・ ・ Slightly good × ・ ・ ・ Defective

Example 1
An epoxy resin composition prepared with the following components A, B and C is impregnated into a PAN-based carbon fiber (strength 350 kg / mm ² , tensile elastic modulus 24 t / mm ² ) aligned in one direction, and the carbon fiber basis weight is obtained. A prepreg having 150 g / m ² , a resin content of about 50 wt% and sandwiching both sides with a polyethylene film and release paper was produced. As shown in Table 1, this prepreg had good storage stability. Next, the polyethylene film was peeled off, the prepreg was adhered to the cement surface treated with the epoxy primer, and pressure was applied while releasing air from the release paper using a trowel and a vibrator. This affixing operation was very simple, and the curing characteristics of the prepreg and the surface condition after curing were good.
• A component: 100 parts by weight of epoxy compound (3: 7 mixture of Epicoat 828 and Epicoat 1002: manufactured by Yuka Shell Epoxy Co., Ltd.) • B component; Polymercaptan compound (Epicure QX-40: Yuka Shell Epoxy Co., Ltd.) ) Produced) 28 parts by weight. C component: 10 parts by weight of microcapsules (average particle size 5 μm) encapsulating 70% by weight of trisdimethylaminomethylphenol and using polyacrylic resin as a shell material.

Example 2
The epoxy resin composition prepared with the components A and B used in Example 1 was impregnated into a plain woven fabric of glass fibers (strength 150 kg / mm ² , tensile elastic modulus 7 t / mm ² ), About 5 parts by weight of the component C used in Example 1 was applied to prepare a prepreg having a glass fiber basis weight of 110 g / m ² , a resin content of about 60 wt%, and both sides sandwiched with a polyethylene film and release paper. When this prepreg was evaluated in the same manner as in Example 1, as shown in Table 1, the storage stability was good, and the pasting workability, the curing characteristics, and the surface condition after curing were good.

Comparative Example 1
The epoxy resin composition adjusted with the components A and B used in Example 1 was impregnated into a PAN-based carbon fiber (strength 350 kg / mm 2, tensile elastic modulus 24 t / mm 2) aligned in one direction, and carbon fiber A prepreg having a basis weight of 150 g / m 2, a resin content of 48 wt%, and both sides sandwiched with a polyethylene film and a release paper was produced. When this prepreg was evaluated in the same manner as in Example 1, the storage stability was good as shown in Table 1, but it did not cure even after 3 weeks at room temperature.
-A component; 100 weight part-B component; 28 weight part

Comparative Example 2
A PAN-based carbon fiber (strength 350 kg / mm ² , tensile elastic modulus 24 t / mm ² ) was used in the same manner as in Example 1 using the epoxy resin composition containing A and B and the following C ′ component used in Example 1. When the prepreg was prepared, the epoxy resin composition was cured while the epoxy resin was being prepared, and the prepreg could not be produced.
· A component: 100 parts by weight · B component: 28 parts by weight · C 'component: Trisdimethylaminomethylphenol-10 parts by weight

Comparative Example 3
An epoxy resin composition prepared with the following components A and B is impregnated into a PAN-based carbon fiber (strength 350 kg / mm 2, tensile elastic modulus 24 t / mm 2) aligned in one direction, and the carbon fiber basis weight is 150 g / m 2. A prepreg having a resin content of 48 wt% and sandwiched between a polyethylene film and release paper on both sides was produced. When this prepreg was evaluated in the same manner as in Example 1, as shown in Table 1, storage stability and pasting workability were good. And although it hardened | cured by heating for 30 minutes at 80 degreeC, it did not harden | cure at room temperature at all even after 3 weeks.
-Component A: 100 parts by weight of epoxy compound (3: 7 mixture of Epicoat 828 and Epicoat 1001)-Component B: 30 parts by weight of latent microcapsule type low temperature curing agent (Novacure HX3722: Asahi Kasei Corporation)

Comparative Example 4
One direction pulls aligned was PAN-based carbon fibers (strength 350 kg / mm ^2, tensile elastic modulus 24t / mm @ 2) in the seat (carbon fiber basis weight 150g / m ^2), was prepared by mixing the components A and B below The epoxy resin solution was adhered to the cement surface treated with an epoxy primer by a hand lay-up method. As shown in Table 1, this affixing operation included an operation of uniformly impregnating the sheet with the epoxy resin solution in addition to the operation of venting air, which was very troublesome. This sheet was completely cured after one week, but some voids were seen on the surface.
-A component: 100 weight part of epoxy compounds (Epicoat 828)-B component: 7 weight part of ethylenediamine

Example 3
An PAN-based carbon fiber (strength 350 kg / mm ² , tensile elastic modulus 24 t / mm ² ) aligned in one direction is impregnated with the epoxy resin composition adjusted with the following components A, B and D, and carbon fiber A prepreg having a basis weight of 150 g / m ² , a resin content of 40 wt%, and both sides sandwiched with a polyethylene film and a release paper was produced. As shown in Table 2, this prepreg had good storage stability. Next, the polyethylene film of the prepreg was peeled off, and affixed to the cemented surface subjected to the epoxy primer treatment while slowly removing a void from the release paper using a roller. After heating it in a constant temperature bath at 70 ° C. for 10 minutes, it was taken out and cooled, and then the release paper was peeled off. This work is not particularly troublesome, and there is no problem in terms of safety and hygiene such as odor, and the attached prepreg is sufficiently cured, and the surface condition is good without any voids. It was.
• A component: 100 parts by weight of an epoxy compound (6: 4 mixture of Epicoat 828 and Epicoat 1002: manufactured by Yuka Shell Epoxy Co., Ltd.) • B component: Polymercaptan compound (Epicure QX-40: Yuka Shell Epoxy Co., Ltd.) 35 parts by weight / D component; microcapsule type latent curing accelerator (Novacure H-3722: manufactured by Asahi Kasei Corporation) 7 parts by weight

Example 4
Glass carbon fibers (strength 150 kg / mm ² , tensile elastic modulus 7 t / mm ² ) aligned in one direction with the epoxy resin composition prepared in A and B components used in Example 3 and the following D component A prepreg having a glass fiber basis weight of 110 g / m ² , a resin content of 35 wt%, and sandwiched between a polyethylene film and a release paper on both sides was produced. As shown in Table 2 , this prepreg had good storage stability. Next, the polyethylene film of the prepreg was peeled off, and affixed to the cemented surface subjected to the epoxy primer treatment while slowly removing a void from the release paper using a roller. After heating it in a thermostat at 60 ° C. for 20 minutes, it was taken out and cooled, and then the release paper was peeled off. This work is not particularly troublesome, and there is no problem in terms of safety and hygiene such as odor, and the attached prepreg is sufficiently cured, and the surface condition is good without any voids. It was.
-A component: 100 parts by weight-B component: 30 parts by weight-D component: 5 parts by weight {Latent curing accelerator (Fujicure FXE-1000: manufactured by Fuji Kasei Co., Ltd.)

Example 5
An epoxy resin composition adjusted with the following components A, B, D, and E is impregnated into glass carbon fiber (strength 150 kg / mm ² , tensile elastic modulus 7 t / mm ² ) aligned in one direction, A prepreg having a glass fiber basis weight of 110 g / m ² , a resin content of 35 wt%, and both sides sandwiched with a polyethylene film and release paper was produced. As shown in Table 2, this prepreg had better storage stability than that of Example 4. Further, the storage stability at 25 ° C. for 10 days was also good. Next, the polyethylene film of the prepreg was peeled off, and affixed to the cemented surface subjected to the epoxy primer treatment while slowly removing a void from the release paper using a roller. After heating it in a thermostat at 60 ° C. for 20 minutes, it was taken out and cooled, and then the release paper was peeled off. This work is not particularly troublesome, and there is no problem in terms of safety and hygiene such as odor, and the attached prepreg is sufficiently cured, and the surface condition is good without any voids. It was.
• A component: 100 parts by weight • B component; 30 parts by weight • D component; 5 parts by weight • E component: 7 parts by weight {Borate ester compound (Careduct L-01B: manufactured by Shikoku Kasei Co., Ltd.)

Example 6
An epoxy resin composition prepared with the following components A, B and D was impregnated into a 12K PAN-based carbon fiber strand (strength 350 kg / mm ² , tensile elastic modulus 24 t / mm ² ), and the resin content was 45 wt%. A strand prepreg was produced. As shown in Table 2, this prepreg had good storage stability. Next, the prepreg was affixed to the surface of a cylindrical cement treated with an epoxy primer while removing voids in quadruple. After heating it in a 60 ° C. constant temperature bath for 20 minutes, it was taken out. This work is not particularly troublesome, and there is no problem in terms of safety and hygiene such as odor, and the attached prepreg is sufficiently cured, and the surface condition is good without any voids. It was.
A component: 100 parts by weight {epoxy compound (7: 3 mixture of Epicoat 828 and Epicoat 1002)}
-B component; 45 weight part {Polymercaptan compound (Adeka Hardener EH-317: manufactured by Asahi Denka Kogyo Co., Ltd.)}
D component: 10 parts by weight {Microcapsule type latent curing accelerator (Novacure H-3722)}

Comparative Example 5
The PAN-based carbon fiber (strength 350 kg / mm ² , tensile elastic modulus 24 t / mm ² ) aligned in one direction was impregnated with the epoxy resin composition adjusted with the components A and B used in Example 3. A prepreg having a carbon fiber basis weight of 150 g / m ² , a resin content of 40 wt%, and both sides sandwiched with a polyethylene film and release paper was produced. This prepreg had good storage stability. This prepreg was evaluated in the same manner as in Example 3. As a result, the workability of attaching was not particularly troublesome, and there was no problem in terms of safety and health, such as odor. However, the attached prepreg was uncured.
-A component; 100 weight part-B component; 35 weight part

Comparative Example 6
The PAN-based carbon fiber (strength: 350 kg / mm ² , tensile elastic modulus: 24 t / mm ² ) aligned in one direction was impregnated with the epoxy resin composition adjusted with components A and D used in Example 3. A prepreg having a carbon fiber basis weight of 150 g / m ² , a resin content of 40 wt%, and both sides sandwiched with a polyethylene film and release paper was produced. This prepreg was an 80 ° C. type low-temperature curable prepreg and had good storage stability. The prepreg was evaluated in the same manner as in Example 3. As a result, the workability of attaching was not particularly troublesome, and there was no problem in terms of safety and health, such as odor. However, the attached prepreg was uncured.
-A component; 100 weight part-D component; 30 weight part

Comparative Example 7
The PAN-based carbon fiber (strength 350 kg / mm ² , tensile elastic modulus) aligned in one direction was prepared from the epoxy resin composition prepared by reducing the blending amount of the D component with the A, B and D components used in Example 3. 24 t / mm ² ) was impregnated to produce a prepreg having a carbon fiber basis weight of 150 g / m ² , a resin content of 40 wt%, and both sides sandwiched with a polyethylene film and release paper. This prepreg had good storage stability. This prepreg was evaluated in the same manner as in Example 3. As a result, the workability of attaching was not particularly troublesome, and there was no problem in terms of safety and health, such as odor. However, the attached prepreg was uncured.
· A component: 100 parts by weight · B component; 35 parts by weight · D component: 0.5 part by weight

Comparative Example 8
The PAN-based carbon fiber (strength 350 kg / mm ² , tensile elastic modulus) aligned in one direction was prepared from the epoxy resin composition in which the blending amount of the D component was adjusted in the A, B and D components used in Example 3. 24 t / mm ² ) was impregnated to produce a prepreg having a carbon fiber basis weight of 150 g / m ² , a resin content of 40 wt%, and both sides sandwiched with a polyethylene film and release paper. This prepreg was poor in storage stability and considerably hardened after 2 days, and the pasting workability as in Example 3 could not be performed.
-A component: 100 parts by weight-B component: 35 parts by weight-D component: 30 parts by weight

Comparative Example 9
A PAN-based carbon fiber (strength 350 kg / mm ² , tensile elastic modulus 24 t / mm ² ) aligned in one direction with an epoxy resin composition prepared with the following components A, B and D (dicyandiamide as component B) A prepreg having a carbon fiber basis weight of 150 g / m ² , a resin content of 40 wt%, and sandwiched between a polyethylene film and a release paper on both sides was produced. This prepreg was a 120 ° C. curable prepreg for general sports / leisure such as golf shafts, and had good storage stability. When this prepreg was evaluated in the same manner as in Example 5, the workability of attaching was not particularly troublesome, and there was no problem in terms of safety and health, such as odor. However, the attached prepreg was uncured.
A component: 100 parts by weight {epoxy compound (mixture of 4 to 6 of Epicoat 828 and Epicoat 1001: manufactured by Yuka Shell Epoxy Co., Ltd.)}
-B component: 4 weight part (dicyandiamide)
-D component; 3 weight part {3- (3,4-dichlorophenyl) -1,1-dimethylurea}

Comparative Example 10
An epoxy resin composition prepared by reducing the amount of component B in components A, B and D used in Example 3 was prepared from a 12K PAN-based carbon fiber strand (strength 350 kg / mm ² , tensile modulus 24 t / mm ^2). ) To produce a strand prepreg having a resin content of 45 wt%. As shown in Table 2, this prepreg had good storage stability. Next, the prepreg was affixed to the surface of the cylindrical cement while removing the voids on the surface of the cylindrical cement. It was taken out after heating for 20 minutes in a constant temperature bath at 60 ° C. This operation was not particularly troublesome and there was no problem in terms of safety and health, such as odor, but the attached prepreg was uncured.
· A component: 100 parts by weight · B component; 4 parts by weight · D component: 7 parts by weight

Comparative Example 11
The PAN-based carbon fiber (strength 350 kg / mm ² , tensile elastic modulus) aligned in one direction was prepared from the epoxy resin composition in which the blending amount of the B component was adjusted with the A, B and D components used in Example 3. 24 t / mm ² ) was impregnated to produce a prepreg having a carbon fiber basis weight of 150 g / m ² , a resin content of 40 wt%, and both sides sandwiched with a polyethylene film and release paper. As shown in Table 2, this prepreg had good storage stability. Next, the prepreg was affixed to the surface of a cylindrical cement treated with an epoxy primer while removing voids in a quadruple manner. It was taken out after heating for 20 minutes in a constant temperature bath at 60 ° C. This operation was not particularly troublesome, and there was no problem in terms of safety and health, such as odor. However, although the prepreg attached was considerably hardened, it was still uncured.
· A component: 100 parts by weight · B component: 120 parts by weight · D component: 7 parts by weight

Comparative Example 12
A pitch system produced by using a 120 ° C curing type resin prepared in Comparative Example 10 after uniformly applying the following components to a cement surface that has been treated with an epoxy primer to a thickness of about 1 mm using a brush. Carbon fiber prepreg (fiber: strength: 370 kg / mm ² , tensile elastic modulus: 40 t / mm ² , carbon fiber basis weight: 100 g / m ² , resin content: 33 wt%) was pasted and evaluated in the same manner as in Example 3 . This prepreg had good storage stability, and there was no particular problem with the workability of application, but due to the use of toluene, there was a problem with safety and hygiene due to the strong odor. The composite material was considerably uncured after one week, and voids were observed on the surface.
Component: Toluene solution containing 80% by weight of 100: 7 mixture of epoxy compound (Epicoat 828) and ethylenediamine

Claims (2)

A low temperature characterized by containing 10 to 100 parts by weight of B component, 1 to 20 parts by weight of D component and 0.1 to 7.0 parts by weight of E component with respect to 100 parts by weight of the following A component Epoxy resin composition for fast- curing prepreg.
A: Epoxy compound B having at least two or more glycidyl groups in one molecule; Polymercaptan compound
D: A microcapsule-type latent curing accelerator that has a potential at room temperature and can be a curing accelerator for a polymercaptan compound.
E: Boric acid ester compound A low-temperature fast- curing prepreg, wherein a reinforcing fiber is impregnated with the epoxy resin composition according to claim 1.